From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: linux-tip-commits@vger.kernel.org,
Andrea Righi <andrea.righi@canonical.com>,
Borislav Petkov <bp@alien8.de>,
x86@kernel.org
Subject: Re: [tip: x86/entry] x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y
Date: Thu, 21 Jan 2021 08:49:28 +0100 [thread overview]
Message-ID: <20210121074928.GA1346795@gmail.com> (raw)
In-Reply-To: <161121327995.414.14890124942899525500.tip-bot2@tip-bot2>
* tip-bot2 for Andrea Righi <tip-bot2@linutronix.de> wrote:
> The following commit has been merged into the x86/entry branch of tip:
>
> Commit-ID: e6d92b6680371ae1aeeb6c5eb2387fdc5d9a2c89
> Gitweb: https://git.kernel.org/tip/e6d92b6680371ae1aeeb6c5eb2387fdc5d9a2c89
> Author: Andrea Righi <andrea.righi@canonical.com>
> AuthorDate: Thu, 14 Jan 2021 12:48:35 +01:00
> Committer: Ingo Molnar <mingo@kernel.org>
> CommitterDate: Thu, 21 Jan 2021 08:11:52 +01:00
>
> x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y
>
> With CONFIG_PREEMPTION disabled, arch/x86/entry/thunk_64.o is just an
> empty object file.
>
> With the newer binutils (tested with 2.35.90.20210113-1ubuntu1) the GNU
> assembler doesn't generate a symbol table for empty object files and
> objtool fails with the following error when a valid symbol table cannot
> be found:
>
> arch/x86/entry/thunk_64.o: warning: objtool: missing symbol table
>
> To prevent this from happening, build thunk_$(BITS).o only if
> CONFIG_PREEMPTION is enabled.
>
> BugLink: https://bugs.launchpad.net/bugs/1911359
>
> Fixes: 320100a5ffe5 ("x86/entry: Remove the TRACE_IRQS cruft")
> Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Link: https://lore.kernel.org/r/YAAvk0UQelq0Ae7+@xps-13-7390
Hm, this fails to build on UML defconfig:
/home/mingo/gcc/cross/lib/gcc/x86_64-linux/9.3.1/../../../../x86_64-linux/bin/ld: arch/x86/um/../entry/thunk_64.o: in function `preempt_schedule_thunk':
/home/mingo/tip.cross/arch/x86/um/../entry/thunk_64.S:34: undefined reference to `preempt_schedule'
/home/mingo/gcc/cross/lib/gcc/x86_64-linux/9.3.1/../../../../x86_64-linux/bin/ld: arch/x86/um/../entry/thunk_64.o: in function `preempt_schedule_notrace_thunk':
/home/mingo/tip.cross/arch/x86/um/../entry/thunk_64.S:35: undefined reference to `preempt_schedule_notrace'
Thanks,
Ingo
next prev parent reply other threads:[~2021-01-21 20:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-14 11:48 [PATCH] x86/entry: build thunk_$(BITS) only if CONFIG_PREEMPTION=y Andrea Righi
2021-01-21 7:14 ` [tip: x86/entry] x86/entry: Build " tip-bot2 for Andrea Righi
2021-01-21 7:49 ` Ingo Molnar [this message]
2021-01-21 8:51 ` Andrea Righi
2021-01-21 10:15 ` Andrea Righi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210121074928.GA1346795@gmail.com \
--to=mingo@kernel.org \
--cc=andrea.righi@canonical.com \
--cc=bp@alien8.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.